Abstract: A silicon carbide epitaxial substrate according to a present disclosure includes a silicon carbide substrate and a silicon carbide epitaxial layer disposed on the silicon carbide substrate. The silicon carbide epitaxial layer includes a boundary surface in contact with the silicon carbide substrate and a main surface opposite to the boundary surface. The main surface has an outer circumferential edge, an outer circumferential region extending within 5 mm from the outer circumferential edge, and a central region surrounded by the outer circumferential region. When an area density of double Shockley stacking faults in the outer circumferential region is defined as a first area density, and an area density of double Shockley stacking faults in the central region is defined as a second area density, the first area density is five or more times as large as the second area density, the second area density is 0.2 cm?2 or more.

Abstract: In a step of calculating formation conditions for the second silicon carbide layer, a formation time of the second silicon carbide layer is calculated as a value obtained by multiplying a value obtained by dividing the second thickness by the first thickness, by the first formation time, and a flow rate of a second ammonia gas in a step of forming the second silicon carbide layer by epitaxial growth is calculated as a value obtained by multiplying a value obtained by dividing the second concentration by the first concentration, by the first flow rate.

Abstract: In a step of calculating formation conditions for the second silicon carbide layer, a formation time of the second silicon carbide layer is calculated as a value obtained by multiplying a value obtained by dividing the second thickness by the first thickness, by the first formation time, and a flow rate of a second ammonia gas in a step of forming the second silicon carbide layer by epitaxial growth is calculated as a value obtained by multiplying a value obtained by dividing the second concentration by the first concentration, by the first flow rate.

Abstract: When a value obtained by dividing the number of the one or more second regions by a total of the number of the one or more first regions and the number of the one or more second regions is defined as a first defect free area ratio, a value obtained by dividing the number of the one or more fourth regions by a total of the number of the one or more third regions and the number of the one or more fourth regions is defined as a second defect free area ratio, and a value obtained by dividing the number of the one or more macroscopic defects by an area of the central region is defined as X cm?2, A is smaller than B, B is less than or equal to 4, X is more than 0 and less than 4, and a Formula 1 is satisfied.

Abstract: A silicon carbide epitaxial substrate has a silicon carbide single-crystal substrate and a silicon carbide layer. An average value of carrier concentration in the silicon carbide layer is not less than 1×1015 cm?3 and not more than 5×1016 cm?3. In-plane uniformity of the carrier concentration is not more than 2%. The second main surface has: a groove 80 extending in one direction along the second main surface, a width of the groove in the one direction being twice or more as large as a width thereof in a direction perpendicular to the one direction, and a maximum depth of the groove from the second main surface being not more than 10 nm; and a carrot defect. A value obtained by dividing a number of the carrot defects by a number of the grooves is not more than 1/500.

Abstract: A silicon carbide epitaxial substrate has a silicon carbide single-crystal substrate and a silicon carbide layer. A first ratio of an absolute value of a difference between a dopant density in a first end region and a dopant density in a central region to an average value of the dopant density in the first end region and the dopant density in the central region is not more than 40%. A second ratio of an absolute value of a difference between a dopant density in a second end region and the dopant density in the central region to an average value of the dopant density in the second end region and the dopant density in the central region is not more than 40%.

Abstract: Assuming that one or more defects satisfying relations of Formula 1 and Formula 2 are first defects, and one or more defects satisfying relations of Formula 3 and Formula 2 are second defects, where an off angle is ?°, the thickness of a silicon carbide layer in a direction perpendicular to a second main surface is W ?m, the width of each of the one or more defects in a direction obtained by projecting a direction parallel to an off direction onto the second main surface is L ?m, and the width of each of the one or more defects in a direction perpendicular to the off direction and parallel to the second main surface is Y ?m, a value obtained by dividing the number of the second defects by the sum of the number of the first defects and the number of the second defects is greater than 0.5.

Abstract: It is assumed that a defect satisfying relations of Formula 1 and Formula 2 is a first defect, where an off angle is ?. It is assumed that a defect having an elongated shape when viewed in a direction perpendicular to the second main surface, and satisfying relations of Formula 3 and Formula 4 is a second defect. A value obtained by dividing the number of the second defect by the sum of the number of the first defect and the number of the second defect is greater than 0.5.

Abstract: A silicon carbide epitaxial substrate has a silicon carbide single-crystal substrate and a silicon carbide layer. An average value of carrier concentration in the silicon carbide layer is not less than 1×1015 cm?3 and not more than 5×1016 cm?3. In-plane uniformity of the carrier concentration is not more than 2%. The second main surface has: a groove 80 extending in one direction along the second main surface, a width of the groove in the one direction being twice or more as large as a width thereof in a direction perpendicular to the one direction, and a maximum depth of the groove from the second main surface being not more than 10 nm; and a carrot defect. A value obtained by dividing a number of the carrot defects by a number of the grooves is not more than 1/500.

Abstract: In forming of a silicon carbide layer, when an X axis indicates a first value representing, in percentage, a value obtained by dividing a flow rate of silane by a flow rate of hydrogen and a Y axis indicates a second value representing a flow rate of ammonia in sccm, the first value and the second value fall within a quadrangular region surrounded by first coordinates, second coordinates, third coordinates, and fourth coordinates in XY plane coordinates. The first coordinates are (0.05, 6.5×10?4). The second coordinates are (0.05, 4.5×10?3). The third coordinates are (0.22, 1.2×10?2). The fourth coordinates are (0.22, 1.3×10?1). After the forming of the silicon carbide layer, an average value of carrier concentration of the silicon carbide layer is more than or equal to 1×1015 cm?3 and less than or equal to 2×1016 cm?3.

Abstract: An epitaxial wafer includes a silicon carbide film having a first main surface. A groove portion is formed in the first main surface. The groove portion extends in one direction along the first main surface. Moreover, a width of the groove portion in the one direction is twice or more as large as a width of the groove portion in a direction perpendicular to the one direction. Moreover, a maximum depth of the groove portion from the first main surface is not more than 10 nm.

Abstract: A silicon carbide epitaxial substrate has a silicon carbide single-crystal substrate and a silicon carbide layer. An average value of carrier concentration in the silicon carbide layer is not less than 1×1015 cm?3 and not more than 5×1016 cm?3. In-plane uniformity of the carrier concentration is not more than 2%. The second main surface has: a groove 80 extending in one direction along the second main surface, a width of the groove in the one direction being twice or more as large as a width thereof in a direction perpendicular to the one direction, and a maximum depth of the groove from the second main surface being not more than 10 nm; and a carrot defect. A value obtained by dividing a number of the carrot defects by a number of the grooves is not more than 1/500.

Abstract: It is assumed that a defect satisfying relations of Formula 1 and Formula 2 is a first defect, where an off angle is ?. It is assumed that a defect having an elongated shape when viewed in a direction perpendicular to the second main surface, and satisfying relations of Formula 3 and Formula 4 is a second defect. A value obtained by dividing the number of the second defect by the sum of the number of the first defect and the number of the second defect is greater than 0.5.

Abstract: A silicon carbide epitaxial substrate has a silicon carbide single-crystal substrate and a silicon carbide layer. An average value of carrier concentration in the silicon carbide layer is not less than 1×1015 cm?3 and not more than 5×10 cm?3. In-plane uniformity of the carrier concentration is not more than 2%. The second main surface has: a groove 80 extending in one direction along the second main surface, a width of the groove in the one direction being twice or more as large as a width thereof in a direction perpendicular to the one direction, and a maximum depth of the groove from the second main surface being not more than 10 nm; and a carrot defect. A value obtained by dividing a number of the carrot defects by a number of the grooves is not more than 1/500.

Abstract: Assuming that one or more defects satisfying relations of Formula 1 and Formula 2 are first defects, and one or more defects satisfying relations of Formula 3 and Formula 2 are second defects, where an off angle is ?°, the thickness of a silicon carbide layer in a direction perpendicular to a second main surface is W ?m, the width of each of the one or more defects in a direction obtained by projecting a direction parallel to an off direction onto the second main surface is L ?m, and the width of each of the one or more defects in a direction perpendicular to the off direction and parallel to the second main surface is Y ?m, a value obtained by dividing the number of the second defects by the sum of the number of the first defects and the number of the second defects is greater than 0.5.

Abstract: An epitaxial wafer includes a silicon carbide film having a first main surface. A groove portion is formed in the first main surface. The groove portion extends in one direction along the first main surface. Moreover, a width of the groove portion in the one direction is twice or more as large as a width of the groove portion in a direction perpendicular to the one direction. Moreover, a maximum depth of the groove portion from the first main surface is not more than 10 nm.

Abstract: A silicon carbide epitaxial substrate includes a silicon carbide single crystal substrate and a silicon carbide layer. The silicon carbide single crystal substrate has a first main surface. The silicon carbide layer is on the first main surface. The silicon carbide layer includes a second main surface opposite to a surface thereof in contact with the silicon carbide single crystal substrate. The second main surface has a maximum diameter of more than or equal to 100 mm. The second main surface includes an outer peripheral region which is within 3 mm from an outer edge of the second main surface, and a central region surrounded by the outer peripheral region. The central region has a haze of less than or equal to 75 ppm.

Abstract: A silicon carbide epitaxial substrate includes a silicon carbide single crystal substrate and a silicon carbide layer. The silicon carbide single crystal substrate has a first main surface. The silicon carbide layer is on the first main surface. The silicon carbide layer includes a second main surface opposite to a surface thereof in contact with the silicon carbide single crystal substrate. The second main surface has a maximum diameter of more than or equal to 100 mm. The second main surface includes an outer peripheral region which is within 3 mm from an outer edge of the second main surface, and a central region surrounded by the outer peripheral region. The central region has a haze of less than or equal to 75 ppm.

Abstract: A silicon carbide epitaxial substrate includes: a silicon carbide single crystal substrate; a first silicon carbide layer on the silicon carbide single crystal substrate, the first silicon carbide layer having a first concentration of carriers; and a second silicon carbide layer on the first silicon carbide layer, the second silicon carbide layer having a second concentration of carriers. A transition region in which the concentration of the carriers is changed between the first concentration and the second concentration has a width of less than or equal to 1 ?m. A ratio of a standard deviation of the second concentration to an average value of the second concentration is less than or equal to 5%, the ratio being defined as uniformity of the second concentration in a central region. The central region has an arithmetic mean roughness of less than or equal to 0.5 nm.

Abstract: The silicon carbide layer has a second main surface. The second main surface has a peripheral region within 5 mm from an outer edge thereof, and a central region surrounded by the peripheral region. The silicon carbide layer has a central surface layer. An average value of a carrier concentration in the central surface layer is not less than 1×1014 cm?3 and not more than 5×1016 cm?3. Circumferential uniformity of the carrier concentration is not more than 2%, and in-plane uniformity of the carrier concentration is not more than 10%. An average value of a thickness of a portion of the silicon carbide layer sandwiched between the central region and the silicon carbide single-crystal substrate is not less than 5 ?m. Circumferential uniformity of the thickness is not more than 1%, and in-plane uniformity of the thickness is not more than 4%.